HELP! no roots-healthy looking phal

[plantaholic]

Had a healthy phal - new growth, several years old - but looked at it tonight and since one leaf looked a little puny, pulled it out of the pot to look at the roots. I wish I'd looked earlier. Had no idea that it was in this bad shape. I'd repotted it about three months ago in bark. I was keeping it in an indoor greenhouse with around 90% humidity, good air circulation, and temps ranging from 70 to 80. It was also in a clear plastic pot with excellent drainage. Any ideas of what to do to possibly save the plant? Is it possible? Any idea of what went wrong? Is it possible to have too much humidity?